US7518675B2 - Method of manufacturing liquid crystal display device - Google Patents

Method of manufacturing liquid crystal display device Download PDF

Info

Publication number
US7518675B2
US7518675B2 US10/572,839 US57283904A US7518675B2 US 7518675 B2 US7518675 B2 US 7518675B2 US 57283904 A US57283904 A US 57283904A US 7518675 B2 US7518675 B2 US 7518675B2
Authority
US
United States
Prior art keywords
film
forming
organic material
liquid crystal
display device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US10/572,839
Other versions
US20070052885A1 (en
Inventor
Hideo Tanaka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Innolux Corp
Original Assignee
TPO Hong Kong Holding Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TPO Hong Kong Holding Ltd filed Critical TPO Hong Kong Holding Ltd
Assigned to KONINKLIJKE PHILIPS ELECTRONICS, N.V. reassignment KONINKLIJKE PHILIPS ELECTRONICS, N.V. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TANAKA, HIDEO
Publication of US20070052885A1 publication Critical patent/US20070052885A1/en
Assigned to TPO HONG KONG HOLDING LIMITED reassignment TPO HONG KONG HOLDING LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KONINKLIJKE PHILIPS ELECTRONICS N.V.
Assigned to TPO HONG KONG HOLDING LIMITED reassignment TPO HONG KONG HOLDING LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KONINKLIJKE PHILIPS ELECTRONICS N.V.
Publication of US7518675B2 publication Critical patent/US7518675B2/en
Application granted granted Critical
Assigned to INNOLUX HONG KONG HOLDING LIMITED reassignment INNOLUX HONG KONG HOLDING LIMITED CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: TPO HONG KONG HOLDING LIMITED
Assigned to INNOLUX HONG KONG HOLDING LIMITED reassignment INNOLUX HONG KONG HOLDING LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Innolux Corporation
Assigned to Innolux Corporation reassignment Innolux Corporation CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE/ASSIGNOR PREVIOUSLY RECORDED AT REEL: 050704 FRAME: 0082. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Assignors: INNOLUX HONG KONG HOLDING LIMITED
Assigned to Innolux Corporation reassignment Innolux Corporation CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNOR/ASSIGNEE PREVIOUSLY RECORDED AT REEL: 050704 FRAME: 0082. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Assignors: INNOLUX HONG KONG HOLDING LIMITED
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133553—Reflecting elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/136227—Through-hole connection of the pixel electrode to the active element through an insulation layer
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/1316—Methods for cleaning the liquid crystal cells, or components thereof, during manufacture: Materials therefor
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133504—Diffusing, scattering, diffracting elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133553—Reflecting elements
    • G02F1/133555—Transflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/136231—Active matrix addressed cells for reducing the number of lithographic steps
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/136231—Active matrix addressed cells for reducing the number of lithographic steps
    • G02F1/136236—Active matrix addressed cells for reducing the number of lithographic steps using a grey or half tone lithographic process

Definitions

  • the present invention relates to a method of manufacturing a liquid crystal display device, in particular to a method of manufacturing a liquid crystal display device exhibiting an improved optical characteristic without increasing photolithography steps.
  • an organic film having projections and depressions is formed as an underlying film of the reflective electrode of a pixel area and the reflective electrode is formed thereon (IDR: In-cell Diffusing Reflector).
  • IDR In-cell Diffusing Reflector
  • the above described method requires two photolithography steps of forming IDR projections and depressions and forming a contact hole. This is not., desirable from the standpoint of mask saving (reduction of photolithography steps).
  • the method of manufacturing a liquid crystal display device is characterized by including a step of forming an organic material film having projections and depressions, using a photo-embossing material, on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device, a step of exposing the insulating film in a contact-hole-forming-area by reducing a thickness of the organic material film due to a dry etching to the organic material film and a step of forming a contact hole by dry etching the exposed insulating film.
  • this method it is possible to realize patterning through exposure and baking without development. This makes it possible to realize steps from the step of forming an organic film to the step of forming a contact hole without any wet processes. This eliminates the necessity for the steps of cleaning and drying which require the developing step, and can improve throughput. Furthermore, this method eliminates the necessity for the photolithography step for forming a contact hole, thus the steps are not complicated.
  • the method of manufacturing a liquid crystal display device preferably comprises a step of exposing the underlying electrode in forming the contact hole and a step of contacting the exposed underlying electrode with a reflective electrode by forming the reflective electrode on the resulting structure.
  • the photo-embossing material is preferably a material patternable by an exposing step and a baking step.
  • the organic material film is preferably formed by exposing and baking the photo-embossing material in forming the organic material film.
  • a halftone mask or a diffraction mask is preferably used in exposing.
  • the dry processes are preferably performed from the step of forming the organic material film to the step of forming the contact hole. Furthermore, in the method of manufacturing a liquid crystal display device according to the present invention, the step of exposing the insulating film and the step of forming the contact hole are preferably performed in a single apparatus.
  • a dry etching process in the step of exposing the insulating film is preferably performed in an Inductively Coupled Plasma mode or a reactive ion etching mode.
  • the liquid crystal display device is preferably a reflective type of liquid crystal display device or a transflective type of liquid crystal display device.
  • FIG. 1 is a sectional view showing a step of a method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention
  • FIG. 2 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention
  • FIG. 3 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention
  • FIG. 4 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
  • FIG. 5 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
  • FIG. 6 is a sectional view showing a liquid crystal display device obtained by the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
  • FIG. 7 is a sectional view showing a step of a method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention.
  • FIG. 8 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention.
  • This embodiment will describe a case where a reflective electrode and source/drain electrodes (underlying electrode) are connected through a contact hole.
  • FIG. 6 is a sectional view showing a part of a liquid crystal display device obtained by a method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
  • the liquid crystal display device is of a transflective type.
  • the parts explained below are areas close to a gate electrode and a gate insulating film of an active matrix type of liquid crystal display device. Therefore, explanations of other parts which have no direct bearing on the present invention are omitted.
  • the structures of these other parts are substantially similar to the conventional structures.
  • a light shield film 12 which prevents light from directly entering a TFT.
  • This light shield film 12 is formed in an area on the glass substrate corresponding to an area including an area (gap) between a source electrode and a drain electrode.
  • a silicon oxide film (e.g., SiO 2 ) 13 which is an inter-layer insulating film is formed on the glass substrate 11 on which the light shield film 12 is formed.
  • a quartz substrate or a transparent plastic substrate instead of the glass substrate.
  • the liquid crystal display device is of a transflective type, such an insulating transparent substrate may be used, but when the liquid crystal display device is of a reflective type, a silicon substrate may also be used. In the case of a reflective type of liquid crystal display device, no light shield film is required.
  • a source electrode and a drain electrode are formed on the silicon oxide film 13 .
  • the source electrode and the drain electrode each have a double-layer structure of an ITO film 14 and a metal film 15 formed on the ITO film 14 , both of which are transparent electrodes.
  • the source electrode and the drain electrode are not limited to the double-layer structure and may also have a one-layer or a three-layer structure.
  • a gap is formed between the source electrode and the drain electrode, and an a-Si film 16 which is a semiconductor film is formed on the gap and on the source electrode and the drain electrode around the gap.
  • a silicon nitride film (e.g., SiN) 17 which is a gate insulating film is formed on the a-Si film 16 .
  • a silicon nitride film 18 which is a gate insulating film is formed on the a-Si film 16 , a silicon nitride film 17 , and a source electrode and a drain electrode.
  • a contact hole 22 is formed in this silicon nitride film (e.g., SiN) 18 .
  • the gate insulating film has a double-layer structure of the silicon nitride films 17 , 18 , but the gate insulating film may also have a one-layer structure.
  • a gate electrode 19 is formed in the area including the gap of the silicon nitride film 18 .
  • An IDR organic material film 20 b is formed on a reflective area (in which a reflective electrode is provided) having such a structure.
  • a photo-embossing material described in EP Patent Application No. 03102200.7 of the present applicant is used as the material of this organic material film 20 b . Projections and depressions are formed on the surface of this organic material film 20 b to provide the reflective electrode with a light diffusing capacity.
  • a reflective electrode 23 is formed on the reflective area of the organic material film 20 b . This reflective electrode 23 is also formed on the side wall of the contact hole 22 . In the contact hole 22 , the metal film 15 other than the portion covered with the reflective electrode 23 is removed and the ITO film 14 is exposed.
  • the material of the gate electrode 19 and the reflective electrode 23 is a commonly used material.
  • the organic material film 20 b having an IDR structure has an uneven shape, and therefore the organic material film 20 b can exhibit sufficient optical effects using the IDR.
  • FIGS. 1 to 6 are sectional views showing steps of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
  • a chromium molybdenum film as an example is coated on the glass substrate 11 and the light shield film 12 is formed by leaving only the chromium molybdenum film of the portion corresponding to the wiring area (including the gap between the source electrode and the drain electrode) through a photolithography step and an etching step.
  • the silicon oxide film 13 which is an inter-layer insulating film is formed on the glass substrate 11 and the light shield film 12 .
  • the ITO film 14 and the metal film 15 are formed on the silicon oxide film 13 one by one and an opening (gap) is formed in the gate area in a photolithography step and an etching step.
  • This opening is provided with a tapered surface whose width decreases toward the silicon oxide film 13 to improve the coverage of the film to be formed thereon.
  • the edge of the ITO film 14 should extend outward more than the edge of the metal film 15 and tapering is preferably provided. Irradiating PH 3 plasma onto such a structure before forming the a-Si film which will be described later causes P atoms to be adsorbed to the surface of the ITO film 14 . As a result, an ohmic characteristic is obtained between the a-Si and ITO.
  • the a-Si film 16 and the silicon nitride film 17 are formed one by one on the metal film 15 having the opening and the a-Si film 16 and the silicon nitride film 17 are left in the gate area (gap, and source and drain electrodes around the gap) through a photolithography step and an etching step.
  • the silicon nitride film 18 which is a gate insulating film is formed on the entire surface of the substrate.
  • a metal film for the gate electrode 19 is further formed thereon.
  • the material of the organic material film 20 is coated thereon to form the organic material film 20 .
  • This organic material film 20 is patterned using a halftone mask 21 .
  • the photo-embossing material described in EP Patent Application No. 03102200.7 of the present applicant is used as the material of this organic material film 20 .
  • This photo-embossing material is a material whose photo-sensitivity is lost by applying a baking step after exposure.
  • an organic material film having projections and depressions is formed using this photo-embossing material, it is possible to realize patterning by using an exposure step and a baking step. This eliminates the necessity for a developing step and makes it possible to omit wet processes.
  • This halftone mask 21 consists of a light shield portion 21 a which shuts off light, a semi-transparent portion 21 b which allows only part of light to pass and a transparent portion 21 c which allows all light to pass.
  • the transparent portion 21 c of the halftone mask 21 is provided so as to correspond to the area of the gate insulating film where the contact hole is formed, the light shield portion 21 a is provided so as to correspond to the area including the convex portion of the IDR organic material film and the semi-concave portion of the IDR organic material film.
  • a dry etching is applied to the organic material film 20 a , the overall thickness of the organic material film 20 a is reduced to expose the silicon nitride film 18 of a contact-hole-forming area X (formation of an opening). That is, the organic material film is left as shown with a dotted line in FIG. 2 through the dry etching.
  • the organic material film 20 a remains on the silicon nitride film 18 of the contact-hole-forming area X, it is preferable to remove the organic material film 20 a using ashing, etc.
  • the used gas and conditions can be modified appropriately within a range in which this purpose can be achieved.
  • the exposed silicon nitride film 18 can be detected by an EPD (End Point Detector).
  • EPD End Point Detector
  • ICP inductively coupled plasma
  • RIE reactive ion etching
  • a dry etching is applied to the structure shown in FIG. 3 to form the contact hole 22 in the area in which the silicon nitride film 18 is exposed as shown in FIG. 4 .
  • etching is performed using the organic material film 20 b as a mask.
  • the used gas and conditions can be modified within a range in which this purpose can be achieved appropriately.
  • patterning can be performed through exposure and baking, that is, using the photo-embossing material capable of patterning without development as the material of the IDR organic material film, it is possible to carry out all steps from the step of forming the organic material film having projections and depressions to the step of forming the contact hole for the insulating film of the base of the organic material film using dry processes (without any wet processes). Therefore, steps from the step of forming the organic material film to the step of forming the contact hole can be performed in a single apparatus, which improves throughput.
  • a metal film is coated on the reflective area (including the organic material film 20 b and the side wall of the silicon nitride film 18 of the contact hole) to form the reflective electrode 23 .
  • the area of the contact hole 22 also serves as a transmission area.
  • Aluminum, etc. can be used as the material of the reflective electrode 23 .
  • the metal film 15 is etched continuously and the ITO film 14 is exposed to form the transmission area. After the etching, the organic material film is peeled. In this way, the underlying electrode (metal film 15 ) and the reflective electrode 23 are connected through the contact hole.
  • an array substrate is created, an opposed substrate is created using a normal method and the array substrate and the opposed substrate are assembled to create a liquid crystal display device.
  • an uneven organic material film is formed on an insulating film on an underlying electrode in a thin-film transistor of an active matrix type of liquid crystal display device using a photo-embossing material, the organic material film is dry etched, the film thickness of the organic material film is reduced, the insulating film of the contact-hole-forming area is exposed, the exposed insulating film is dry etched and a contact hole is formed.
  • the material constituting this organic material film can be patterned through exposure and baking without development, and therefore it is possible to realize steps from the step of forming the organic material film to the step of forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step and can improve throughput. Furthermore, this method does not require any photolithography step to form the contact hole, thus the steps are not complicated.
  • the liquid crystal display device obtained in this method can form an organic material film having projections and depressions on the surface, and can thereby exhibit the IDR effect as in the conventional art.
  • FIGS. 7 and 8 are sectional views showing steps of a method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention.
  • the left side from the dotted line is a panel area and the right side from the dotted line (outside the sealed area) is a terminal-forming area Y.
  • a silicon oxide film 13 is formed on a glass substrate, an ITO film 14 and a metal film 15 are formed thereon one by one and these films are patterned. At this time, patterning is performed so that the ITO film 14 and metal film 15 , and gate electrode 19 do not overlap with each other. Patterning may also be performed so that the ITO film 14 and metal film 15 , and gate electrode 19 overlap with each other.
  • a silicon nitride film 18 is formed on the metal film 15 , the gate electrode 19 is formed thereon and then an IDR organic material film is formed. Then, this organic material film is patterned through exposure and baking using a halftone mask as in the case of Embodiment 1 and then dry etched in such a way that an organic material film 20 b is left. This causes the silicon nitride film 18 in the contact-hole-forming area X and terminal-forming area Y to be exposed.
  • the silicon nitride film 18 is dry etched using the organic material film 20 b as a mask and then a reflective electrode 23 is formed thereon. This reflective electrode 23 is patterned so that the gate electrode 19 and the metal film 15 are connected.
  • the silicon nitride film 18 is dry etched using the organic material film 20 b as a mask, and then the metal film 15 is etched using the etched silicon nitride film 18 as a mask. A terminal is formed in this way.
  • an uneven organic material film is formed on an insulating film using a photo-embossing material, a dry etching is applied to the organic material film, the thickness of the organic material film is reduced, the insulating film of the contact-hole-forming area in the terminal-forming area is exposed and the exposed insulating film is dry etched to form a contact hole.
  • the material constituting this organic material film can be patterned through exposure and baking without development, and therefore it is possible to realize steps from forming the organic material film to forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step and can improve throughput. Furthermore, this method does not require any photolithography step to form the contact hole, thus the steps are not complicated.
  • the liquid crystal display device obtained in this method can form an organic material film having projections and depressions on the surface, and can thereby exhibit the IDR effect as in the conventional art.
  • Embodiment 1, 2 can be implemented with the material and the used gas, etc., modified in various ways.
  • the material and the structure used in Embodiments 1, 2 are not limited and it is possible to use an alternate material and an alternate structure which can exhibit the same functions. That is, Embodiments 1, 2 have explained the case where a silicon oxide film is used as an inter-layer insulating film, a silicon nitride film is used as a gate insulating film and a chromium film is used as a light shield film.
  • any other materials can be used if they at least exhibit equivalent functions.
  • the thickness of each film is not particularly limited if each film at least exhibits the function of the film.
  • Embodiments 1, 2 have explained the case where a halftone mask is used, but in the present invention, it is also possible to form an organic material film having a thick film section and opening by using a diffraction mask having a light shield portion, a transparent portion and a semi-transparent portion (micro pattern section equal to or smaller than a resolution limit).
  • a diffraction mask having a light shield portion, a transparent portion and a semi-transparent portion (micro pattern section equal to or smaller than a resolution limit).
  • a small pattern equal to or smaller than a resolution limit of the exposure device is formed and this part is used as the semi-transparent portion.
  • the weak light passes through the mask.
  • Embodiments 1, 2 have explained the case where the liquid crystal display device is of a transflective type, but the present invention is likewise applicable to a case where the liquid crystal display device is of a reflective type.
  • the case of the reflective type is substantially the same as the case of the transflective type except that the light shield film is not necessary and the reflective electrode is also formed in the opening of the silicon nitride film, etc.
  • an organic material film having projections and depressions is formed using a photo-embossing material, on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device, the insulating film in a contact-hole-forming-area is exposed by reducing a thickness of the organic material film due to a dry etching to the organic material film and a contact hole is formed by dry etching the exposed insulating film, and therefore patterning can be performed through exposure and baking without development.
  • This makes it possible to realize steps from the step of forming the organic film to the step of forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step, and can thereby improve throughput.
  • this method eliminates the necessity for the photolithography step for forming the contact hole, thus the steps are not complicated.
  • the present invention is applicable to a reflective type of liquid crystal display device and a transflective type of liquid crystal display device.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Engineering & Computer Science (AREA)
  • Liquid Crystal (AREA)
  • Thin Film Transistor (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
  • Saccharide Compounds (AREA)
  • Compounds Of Unknown Constitution (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Drying Of Semiconductors (AREA)

Abstract

A method of the present invention includes the steps of forming an organic material film having projections and depressions, using a photo-embossing material, on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device; exposing the insulating film in a contact-hole-forming-area by reducing a thickness of the organic material film by a dry etching to said organic material film; forming a contact hole and exposing the underlying by a dry etching to the exposed insulating film; and contacting the exposed underlying electrode with a reflective electrode by forming the reflective electrode on the resulting structure.

Description

TECHNICAL FIELD
The present invention relates to a method of manufacturing a liquid crystal display device, in particular to a method of manufacturing a liquid crystal display device exhibiting an improved optical characteristic without increasing photolithography steps.
BACKGROUND ART
In order to improve an optical diffusion characteristic of a reflective electrode in an active matrix type of liquid crystal display device, an organic film having projections and depressions is formed as an underlying film of the reflective electrode of a pixel area and the reflective electrode is formed thereon (IDR: In-cell Diffusing Reflector). When a contact hole is formed on a gate insulating film of a thin-film transistor (TFT), after the TFT is formed, projections and depressions are formed for the IDR in the reflective area in a photolithography step, and then the contact hole is formed on the gate insulating film using a mask for forming a contact hole in a photolithography step and an etching step.
However, the above described method requires two photolithography steps of forming IDR projections and depressions and forming a contact hole. This is not., desirable from the standpoint of mask saving (reduction of photolithography steps).
DISCLOSURE
It is an object of the present invention to provide a method of manufacturing a liquid crystal display device which is able to obtain a liquid crystal display device exhibiting an improved optical characteristic without increasing photolithography steps.
The method of manufacturing a liquid crystal display device according to the present invention is characterized by including a step of forming an organic material film having projections and depressions, using a photo-embossing material, on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device, a step of exposing the insulating film in a contact-hole-forming-area by reducing a thickness of the organic material film due to a dry etching to the organic material film and a step of forming a contact hole by dry etching the exposed insulating film.
According to this method, it is possible to realize patterning through exposure and baking without development. This makes it possible to realize steps from the step of forming an organic film to the step of forming a contact hole without any wet processes. This eliminates the necessity for the steps of cleaning and drying which require the developing step, and can improve throughput. Furthermore, this method eliminates the necessity for the photolithography step for forming a contact hole, thus the steps are not complicated.
The method of manufacturing a liquid crystal display device according to the present invention preferably comprises a step of exposing the underlying electrode in forming the contact hole and a step of contacting the exposed underlying electrode with a reflective electrode by forming the reflective electrode on the resulting structure.
In the method of manufacturing a liquid crystal display device according to the present invention, the photo-embossing material is preferably a material patternable by an exposing step and a baking step. In this case, the organic material film is preferably formed by exposing and baking the photo-embossing material in forming the organic material film. Furthermore, in this case, a halftone mask or a diffraction mask is preferably used in exposing.
In the method of manufacturing a liquid crystal display device according to the present invention, the dry processes are preferably performed from the step of forming the organic material film to the step of forming the contact hole. Furthermore, in the method of manufacturing a liquid crystal display device according to the present invention, the step of exposing the insulating film and the step of forming the contact hole are preferably performed in a single apparatus.
In the method of manufacturing a liquid crystal display device according to the present invention, a dry etching process in the step of exposing the insulating film is preferably performed in an Inductively Coupled Plasma mode or a reactive ion etching mode.
In the method of manufacturing a liquid crystal display device according to the present invention, the liquid crystal display device is preferably a reflective type of liquid crystal display device or a transflective type of liquid crystal display device.
DESCRIPTION OF DRAWINGS
FIG. 1 is a sectional view showing a step of a method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 2 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 3 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 4 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 5 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 6 is a sectional view showing a liquid crystal display device obtained by the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention;
FIG. 7 is a sectional view showing a step of a method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention; and
FIG. 8 is a sectional view showing a step of the method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention.
 BEST MODE
With reference now to the attached drawings, embodiments of the present invention will be explained in detail below.
EMBODIMENT 1
This embodiment will describe a case where a reflective electrode and source/drain electrodes (underlying electrode) are connected through a contact hole.
FIG. 6 is a sectional view showing a part of a liquid crystal display device obtained by a method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention. Hereinafter, a case where the liquid crystal display device is of a transflective type will be explained. The parts explained below are areas close to a gate electrode and a gate insulating film of an active matrix type of liquid crystal display device. Therefore, explanations of other parts which have no direct bearing on the present invention are omitted. The structures of these other parts are substantially similar to the conventional structures.
On one principal surface of a glass substrate 11 which is an insulating transparent substrate is a light shield film 12 which prevents light from directly entering a TFT. This light shield film 12 is formed in an area on the glass substrate corresponding to an area including an area (gap) between a source electrode and a drain electrode. A silicon oxide film (e.g., SiO2) 13 which is an inter-layer insulating film is formed on the glass substrate 11 on which the light shield film 12 is formed. Here, it is also possible to use a quartz substrate or a transparent plastic substrate instead of the glass substrate. When the liquid crystal display device is of a transflective type, such an insulating transparent substrate may be used, but when the liquid crystal display device is of a reflective type, a silicon substrate may also be used. In the case of a reflective type of liquid crystal display device, no light shield film is required.
A source electrode and a drain electrode are formed on the silicon oxide film 13. The source electrode and the drain electrode each have a double-layer structure of an ITO film 14 and a metal film 15 formed on the ITO film 14, both of which are transparent electrodes. The source electrode and the drain electrode are not limited to the double-layer structure and may also have a one-layer or a three-layer structure. A gap is formed between the source electrode and the drain electrode, and an a-Si film 16 which is a semiconductor film is formed on the gap and on the source electrode and the drain electrode around the gap.
A silicon nitride film (e.g., SiN) 17 which is a gate insulating film is formed on the a-Si film 16. A silicon nitride film 18 which is a gate insulating film is formed on the a-Si film 16, a silicon nitride film 17, and a source electrode and a drain electrode. A contact hole 22 is formed in this silicon nitride film (e.g., SiN) 18. Now, the case where the gate insulating film has a double-layer structure of the silicon nitride films 17, 18, but the gate insulating film may also have a one-layer structure.
In the area including the gap of the silicon nitride film 18, a gate electrode 19 is formed. An IDR organic material film 20 b is formed on a reflective area (in which a reflective electrode is provided) having such a structure. A photo-embossing material described in EP Patent Application No. 03102200.7 of the present applicant is used as the material of this organic material film 20 b. Projections and depressions are formed on the surface of this organic material film 20 b to provide the reflective electrode with a light diffusing capacity. A reflective electrode 23 is formed on the reflective area of the organic material film 20 b. This reflective electrode 23 is also formed on the side wall of the contact hole 22. In the contact hole 22, the metal film 15 other than the portion covered with the reflective electrode 23 is removed and the ITO film 14 is exposed. The material of the gate electrode 19 and the reflective electrode 23 is a commonly used material.
In the liquid crystal display device having such a structure, the organic material film 20 b having an IDR structure has an uneven shape, and therefore the organic material film 20 b can exhibit sufficient optical effects using the IDR.
Next, the method of manufacturing the liquid crystal display device according to Embodiment 1 of the present invention will be explained using FIGS. 1 to 6. FIGS. 1 to 6 are sectional views showing steps of the method of manufacturing a liquid crystal display device according to Embodiment 1 of the present invention.
As shown in FIG. 1, a chromium molybdenum film as an example is coated on the glass substrate 11 and the light shield film 12 is formed by leaving only the chromium molybdenum film of the portion corresponding to the wiring area (including the gap between the source electrode and the drain electrode) through a photolithography step and an etching step. Next, the silicon oxide film 13 which is an inter-layer insulating film is formed on the glass substrate 11 and the light shield film 12.
Next, the ITO film 14 and the metal film 15 are formed on the silicon oxide film 13 one by one and an opening (gap) is formed in the gate area in a photolithography step and an etching step. This opening is provided with a tapered surface whose width decreases toward the silicon oxide film 13 to improve the coverage of the film to be formed thereon. In the structure of this portion, it is essential that the edge of the ITO film 14 should extend outward more than the edge of the metal film 15 and tapering is preferably provided. Irradiating PH3 plasma onto such a structure before forming the a-Si film which will be described later causes P atoms to be adsorbed to the surface of the ITO film 14. As a result, an ohmic characteristic is obtained between the a-Si and ITO.
Then, the a-Si film 16 and the silicon nitride film 17 are formed one by one on the metal film 15 having the opening and the a-Si film 16 and the silicon nitride film 17 are left in the gate area (gap, and source and drain electrodes around the gap) through a photolithography step and an etching step.
Next, the silicon nitride film 18 which is a gate insulating film is formed on the entire surface of the substrate. A metal film for the gate electrode 19 is further formed thereon. On top of it, the material of the organic material film 20 is coated thereon to form the organic material film 20. This organic material film 20 is patterned using a halftone mask 21.
Now, the photo-embossing material described in EP Patent Application No. 03102200.7 of the present applicant is used as the material of this organic material film 20. The entire disclosure of the content of this application is incorporated herein by reference in its entirety. This photo-embossing material is a material whose photo-sensitivity is lost by applying a baking step after exposure. When an organic material film having projections and depressions is formed using this photo-embossing material, it is possible to realize patterning by using an exposure step and a baking step. This eliminates the necessity for a developing step and makes it possible to omit wet processes.
This halftone mask 21 consists of a light shield portion 21 a which shuts off light, a semi-transparent portion 21 b which allows only part of light to pass and a transparent portion 21 c which allows all light to pass. The transparent portion 21 c of the halftone mask 21 is provided so as to correspond to the area of the gate insulating film where the contact hole is formed, the light shield portion 21 a is provided so as to correspond to the area including the convex portion of the IDR organic material film and the semi-concave portion of the IDR organic material film.
When the photo-embossing material is exposed to light using this halftone mask 21, as shown in FIG. 2, all exposure light passes through the transparent portion 21 c and a part of the exposure light passes through the semi-transparent portion 21 b. On the other hand, no exposure light passes through the light shield portion 21 a. That is, most of the photo-embossing material of the area corresponding to the transparent portion 21 c is removed and what remains is the thinnest of all. On the other hand, the photo-embossing material of the area corresponding to the semi-transparent portion 21 b is partially removed. All of the photo-embossing materials of the area corresponding to the light shield portion 21 a remain. A baking step is applied to the remaining organic material film 20 a to harden the photo-embossing material. This results in the organic material film 20 a having projections and depressions.
Next, a dry etching is applied to the organic material film 20 a, the overall thickness of the organic material film 20 a is reduced to expose the silicon nitride film 18 of a contact-hole-forming area X (formation of an opening). That is, the organic material film is left as shown with a dotted line in FIG. 2 through the dry etching. At this time, when the organic material film 20 a remains on the silicon nitride film 18 of the contact-hole-forming area X, it is preferable to remove the organic material film 20 a using ashing, etc.
Since this dry etching is performed to remove the organic material film 20 a in the area in which the contact hole is formed, the used gas and conditions can be modified appropriately within a range in which this purpose can be achieved. Furthermore, the exposed silicon nitride film 18 (contact-hole-forming area) can be detected by an EPD (End Point Detector). Furthermore, it is possible to reduce the thickness of the organic material film 20 a uniformly by carrying out a dry etching in an inductively coupled plasma (ICP) mode or a reactive ion etching (RIE) mode, and therefore the uneven shape can be kept after the dry etching. In this way, it is possible to prevent the diffuse reflection characteristic from being degraded.
Next, a dry etching is applied to the structure shown in FIG. 3 to form the contact hole 22 in the area in which the silicon nitride film 18 is exposed as shown in FIG. 4. At this time, etching is performed using the organic material film 20 b as a mask.
Since this dry etching is performed to form the contact hole, the used gas and conditions can be modified within a range in which this purpose can be achieved appropriately.
Thus, patterning can be performed through exposure and baking, that is, using the photo-embossing material capable of patterning without development as the material of the IDR organic material film, it is possible to carry out all steps from the step of forming the organic material film having projections and depressions to the step of forming the contact hole for the insulating film of the base of the organic material film using dry processes (without any wet processes). Therefore, steps from the step of forming the organic material film to the step of forming the contact hole can be performed in a single apparatus, which improves throughput.
Next, as shown in FIG. 5, a metal film is coated on the reflective area (including the organic material film 20 b and the side wall of the silicon nitride film 18 of the contact hole) to form the reflective electrode 23. Now, the area of the contact hole 22 also serves as a transmission area. Aluminum, etc., can be used as the material of the reflective electrode 23. Next, as shown in FIG. 6, using the same resist pattern of the reflective electrode 23, the metal film 15 is etched continuously and the ITO film 14 is exposed to form the transmission area. After the etching, the organic material film is peeled. In this way, the underlying electrode (metal film 15) and the reflective electrode 23 are connected through the contact hole. Using aluminum as the material of the reflective electrode 23 and a chromium molybdenum alloy as the material of the metal film 15, it is possible to use a single etchant, and therefore it is possible to use the same resist pattern of the reflective electrode 23 to dry-etch the metal film 15 continuously as described above.
In this way, an array substrate is created, an opposed substrate is created using a normal method and the array substrate and the opposed substrate are assembled to create a liquid crystal display device.
Thus, according to the method of this embodiment, an uneven organic material film is formed on an insulating film on an underlying electrode in a thin-film transistor of an active matrix type of liquid crystal display device using a photo-embossing material, the organic material film is dry etched, the film thickness of the organic material film is reduced, the insulating film of the contact-hole-forming area is exposed, the exposed insulating film is dry etched and a contact hole is formed.
The material constituting this organic material film can be patterned through exposure and baking without development, and therefore it is possible to realize steps from the step of forming the organic material film to the step of forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step and can improve throughput. Furthermore, this method does not require any photolithography step to form the contact hole, thus the steps are not complicated. The liquid crystal display device obtained in this method can form an organic material film having projections and depressions on the surface, and can thereby exhibit the IDR effect as in the conventional art.
EMBODIMENT 2
This embodiment will describe a case where the present invention is applied to a terminal-forming position outside a panel. FIGS. 7 and 8 are sectional views showing steps of a method of manufacturing a liquid crystal display device according to Embodiment 2 of the present invention. In FIGS. 7 and 8, the left side from the dotted line is a panel area and the right side from the dotted line (outside the sealed area) is a terminal-forming area Y.
A silicon oxide film 13 is formed on a glass substrate, an ITO film 14 and a metal film 15 are formed thereon one by one and these films are patterned. At this time, patterning is performed so that the ITO film 14 and metal film 15, and gate electrode 19 do not overlap with each other. Patterning may also be performed so that the ITO film 14 and metal film 15, and gate electrode 19 overlap with each other. A silicon nitride film 18 is formed on the metal film 15, the gate electrode 19 is formed thereon and then an IDR organic material film is formed. Then, this organic material film is patterned through exposure and baking using a halftone mask as in the case of Embodiment 1 and then dry etched in such a way that an organic material film 20 b is left. This causes the silicon nitride film 18 in the contact-hole-forming area X and terminal-forming area Y to be exposed.
Next, as shown in FIG. 8, the silicon nitride film 18 is dry etched using the organic material film 20 b as a mask and then a reflective electrode 23 is formed thereon. This reflective electrode 23 is patterned so that the gate electrode 19 and the metal film 15 are connected. On the other hand, in the terminal-forming area Y, the silicon nitride film 18 is dry etched using the organic material film 20 b as a mask, and then the metal film 15 is etched using the etched silicon nitride film 18 as a mask. A terminal is formed in this way.
The dry etching conditions, etc., are the same as those in Embodiment 1.
Thus, according to the method of this embodiment, an uneven organic material film is formed on an insulating film using a photo-embossing material, a dry etching is applied to the organic material film, the thickness of the organic material film is reduced, the insulating film of the contact-hole-forming area in the terminal-forming area is exposed and the exposed insulating film is dry etched to form a contact hole.
The material constituting this organic material film can be patterned through exposure and baking without development, and therefore it is possible to realize steps from forming the organic material film to forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step and can improve throughput. Furthermore, this method does not require any photolithography step to form the contact hole, thus the steps are not complicated. The liquid crystal display device obtained in this method can form an organic material film having projections and depressions on the surface, and can thereby exhibit the IDR effect as in the conventional art.
The present invention is not limited to Embodiment 1, 2 and can be implemented with the material and the used gas, etc., modified in various ways. For example, the material and the structure used in Embodiments 1, 2 are not limited and it is possible to use an alternate material and an alternate structure which can exhibit the same functions. That is, Embodiments 1, 2 have explained the case where a silicon oxide film is used as an inter-layer insulating film, a silicon nitride film is used as a gate insulating film and a chromium film is used as a light shield film. However, in the present invention, any other materials can be used if they at least exhibit equivalent functions. Furthermore, the thickness of each film is not particularly limited if each film at least exhibits the function of the film.
Furthermore, Embodiments 1, 2 have explained the case where a halftone mask is used, but in the present invention, it is also possible to form an organic material film having a thick film section and opening by using a diffraction mask having a light shield portion, a transparent portion and a semi-transparent portion (micro pattern section equal to or smaller than a resolution limit). In the case of this diffraction mask, a small pattern equal to or smaller than a resolution limit of the exposure device is formed and this part is used as the semi-transparent portion. When light is diffracted with this small pattern, the weak light passes through the mask.
Embodiments 1, 2 have explained the case where the liquid crystal display device is of a transflective type, but the present invention is likewise applicable to a case where the liquid crystal display device is of a reflective type. The case of the reflective type is substantially the same as the case of the transflective type except that the light shield film is not necessary and the reflective electrode is also formed in the opening of the silicon nitride film, etc.
As described above, according to the method of manufacturing a liquid crystal display device, an organic material film having projections and depressions is formed using a photo-embossing material, on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device, the insulating film in a contact-hole-forming-area is exposed by reducing a thickness of the organic material film due to a dry etching to the organic material film and a contact hole is formed by dry etching the exposed insulating film, and therefore patterning can be performed through exposure and baking without development. This makes it possible to realize steps from the step of forming the organic film to the step of forming the contact hole without any wet processes. This eliminates the necessity for the cleaning/drying steps required in the developing step, and can thereby improve throughput. Furthermore, this method eliminates the necessity for the photolithography step for forming the contact hole, thus the steps are not complicated.
INDUSTRIAL APPLICABILITY
The present invention is applicable to a reflective type of liquid crystal display device and a transflective type of liquid crystal display device.

Claims (19)

1. A method of manufacturing liquid crystal display device comprising the steps of:
forming an organic material film having projections and depressions, using a photo-embossing material on an insulating film on an underlying electrode in a thin-film transistor of an active-matrix liquid crystal display device;
exposing said insulating film in a contact-hole-forming-area by reducing a thickness of said organic material film by a day etching to said organic material film; and
forming a contact hole by a dry etching to the exposed insulating film, wherein the projections and depressions of the organic material film are formed by subjecting the photo-embossing material to a mask and exposure to light, wherein the projections and depressions in the organic material film include a thinnest region corresponding to the contact-hole-forming area.
2. A method as claimed in claim 1, further comprising the steps of:
exposing said underlying electrode in forming said contact hole; and
contacting the exposed underlying electrode with a reflective electrode by forming said reflective electrode on the resulting structure.
3. A method as claimed in claim 1, wherein said photo-embossing material is a material patternable by an exposing step and a baking step.
4. A method as claimed in claim 3, wherein said organic material film is formed by exposing and baking said photo-embossing material in forming said organic material film.
5. A method as claimed in claim 4, wherein a halftone mask or a diffraction mask is used in exposing.
6. A method as claimed in claim 1, wherein dry processes are performed from the step of forming said organic material film to the step of forming said contact hole.
7. A method as claimed in claim 1, wherein the step of exposing said insulating film and the step of forming said contact hole are performed in a single apparatus.
8. A method as claimed in claim 1, wherein the dry etching in the step of exposing said insulating film is performed in an Inductively Coupled Plasma mode or a reactive ion etching mode.
9. A method as claimed in claim 1, wherein said liquid crystal display device is a reflective type of liquid crystal display device or a transflective type of liquid crystal display device.
10. A method as in claim 1, wherein the mask comprises a light shield portions corresponding to the projections, semi-transparent regions corresponding to the depressions, and a transparent portion corresponding to the thinnest region in the organic material film.
11. A method as in claim 1, wherein the insulating film is exposed by dry etching the thinnest region of the organic material film.
12. A method of manufacturing a liquid crystal display device comprising:
forming a thin-film transistor on a substrate;
forming an insulating film over the thin-film transistor;
disposing an organic material film above the insulating film;
forming projections and depressions in the organic material film, including a thinnest region corresponding, to a contact-hole-forming-area;
dry etching the thinnest region of the organic material film to expose a region of the insulating film; and
dry etching the exposed region of the insulating film to form a contact hole.
13. The method as in claim 12, wherein the organic material film comprises a photo-embossing material, wherein the projections and depressions are formed by subjecting the photo-embossing material to a mask and exposure to light.
14. The method as in claim 13, wherein the mask comprises a light shield portions corresponding to the projections, semi-transparent regions corresponding to the depressions, and a transparent portion corresponding to the thinnest region in the organic material film.
15. The method as in claim 12, further comprising the steps of forming an electrode layer below the insulating layer, wherein a region of the electrode is exposed after the contact hole is formed; and forming a reflective electrode above the projections and depressions and the exposed region of the electrode layer, wherein the reflective electrode contacts the exposed region of the electrode layer.
16. The method as in claim 12, wherein only dry processes are performed from forming said projections and depressions in the organic material film to forming said contact hole.
17. The method as in claim 12, wherein dry etching the thinnest region of the organic material film and dry etching the exposed region of the insulating film axe performed in a single apparatus.
18. The method as in claim 12, wherein dry etching to expose the insulating film is performed in an inductively coupled plasma mode or a reactive ion etching mode.
19. The method as in claim 12, wherein said liquid crystal display device is a reflective type liquid crystal display device or a transflective type of liquid crystal display device.
US10/572,839 2003-09-22 2004-09-17 Method of manufacturing liquid crystal display device Expired - Fee Related US7518675B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IB0304248 2003-09-22
WOPCT/IB03/04248 2003-09-22
PCT/IB2004/051784 WO2005029169A1 (en) 2003-09-22 2004-09-17 Method of manufacturing liquid crystal display device

Publications (2)

Publication Number Publication Date
US20070052885A1 US20070052885A1 (en) 2007-03-08
US7518675B2 true US7518675B2 (en) 2009-04-14

Family

ID=34362336

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/572,839 Expired - Fee Related US7518675B2 (en) 2003-09-22 2004-09-17 Method of manufacturing liquid crystal display device

Country Status (9)

Country Link
US (1) US7518675B2 (en)
EP (1) EP1668406B1 (en)
JP (1) JP5079330B2 (en)
KR (1) KR101027979B1 (en)
CN (1) CN100468156C (en)
AT (1) ATE503204T1 (en)
DE (1) DE602004031959D1 (en)
TW (1) TWI364575B (en)
WO (1) WO2005029169A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070105340A1 (en) * 2005-10-07 2007-05-10 Ulrich Todt Interlayer bond to a substrate which, at least in regions on a surface, is provided with a coating of a metal, a method for production thereof and use
US20140204323A1 (en) * 2013-01-21 2014-07-24 Samsung Display Co., Ltd. Liquid crystal display and a method of manufacturing the same

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2492780B1 (en) * 2009-11-26 2014-07-02 Sharp Kabushiki Kaisha A touch panel manufacturing method, and a method for manufacturing a display device provided with a touch panel
GB2489940A (en) * 2011-04-11 2012-10-17 Plastic Logic Ltd Reflective pixel element for reflective display devices
TWI435152B (en) 2011-08-16 2014-04-21 Chunghwa Picture Tubes Ltd Method for forming contact hole
WO2015139979A1 (en) * 2014-03-21 2015-09-24 Koninklijke Philips N.V. Cmut device and manufacturing method
CN107515498B (en) * 2017-09-18 2020-06-05 上海天马微电子有限公司 Array substrate and display panel
CN110941126B (en) 2019-12-27 2021-04-27 Tcl华星光电技术有限公司 Array substrate and manufacturing method thereof

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5949507A (en) * 1995-11-28 1999-09-07 Sharp Kabushiki Kaisha Active matrix substrate and liquid crystal display apparatus having electrical continuity across contact holes, and method for producing the same
US20020063825A1 (en) 2000-11-30 2002-05-30 Nec Corporation Reflection type liquid crystal display device and process for manufacturing the same
US20020101556A1 (en) 2001-01-31 2002-08-01 Nec Corporation Liquid crystal display device and method of fabricating the same
US20020158995A1 (en) 2001-04-26 2002-10-31 Chang-Won Hwang Polycrystalline silicon thin film transistor of liquid crystal display and manufacturing method thereof
US20020159010A1 (en) 2001-04-26 2002-10-31 Nec Corporation Liquid crystal display device and manufacturing method of same
US20030086036A1 (en) * 2001-10-22 2003-05-08 Samsung Electronics Co., Ltd. Liquid crystal display for enhancing reflection and method of manufacturing the same
US7176994B2 (en) * 2001-03-29 2007-02-13 Nec Lcd Technologies, Ltd Liquid crystal display panel having reflection electrodes improved in smooth surface morphology and process for fabrication thereof

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000349301A (en) * 1999-04-01 2000-12-15 Semiconductor Energy Lab Co Ltd Semiconductor device and its manufacture
JP2000353649A (en) * 1999-06-09 2000-12-19 Tokyo Electron Ltd Method and apparatus for processing substrate
JP2001194662A (en) * 2000-01-14 2001-07-19 Nec Corp Reflection type liquid crystal display device and its manufacturing method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5949507A (en) * 1995-11-28 1999-09-07 Sharp Kabushiki Kaisha Active matrix substrate and liquid crystal display apparatus having electrical continuity across contact holes, and method for producing the same
US20020063825A1 (en) 2000-11-30 2002-05-30 Nec Corporation Reflection type liquid crystal display device and process for manufacturing the same
US20020101556A1 (en) 2001-01-31 2002-08-01 Nec Corporation Liquid crystal display device and method of fabricating the same
US7176994B2 (en) * 2001-03-29 2007-02-13 Nec Lcd Technologies, Ltd Liquid crystal display panel having reflection electrodes improved in smooth surface morphology and process for fabrication thereof
US20020158995A1 (en) 2001-04-26 2002-10-31 Chang-Won Hwang Polycrystalline silicon thin film transistor of liquid crystal display and manufacturing method thereof
US20020159010A1 (en) 2001-04-26 2002-10-31 Nec Corporation Liquid crystal display device and manufacturing method of same
US20030086036A1 (en) * 2001-10-22 2003-05-08 Samsung Electronics Co., Ltd. Liquid crystal display for enhancing reflection and method of manufacturing the same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PCT International Search Report of Counterpart PCT Application No. PCT/IB2004/051784.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070105340A1 (en) * 2005-10-07 2007-05-10 Ulrich Todt Interlayer bond to a substrate which, at least in regions on a surface, is provided with a coating of a metal, a method for production thereof and use
US20140204323A1 (en) * 2013-01-21 2014-07-24 Samsung Display Co., Ltd. Liquid crystal display and a method of manufacturing the same
US9488889B2 (en) * 2013-01-21 2016-11-08 Samsung Display Co., Ltd. Liquid crystal display and a method of manufacturing the same

Also Published As

Publication number Publication date
ATE503204T1 (en) 2011-04-15
CN100468156C (en) 2009-03-11
CN1856731A (en) 2006-11-01
TWI364575B (en) 2012-05-21
KR20070017467A (en) 2007-02-12
US20070052885A1 (en) 2007-03-08
TW200515047A (en) 2005-05-01
KR101027979B1 (en) 2011-04-13
JP2007506134A (en) 2007-03-15
EP1668406A1 (en) 2006-06-14
JP5079330B2 (en) 2012-11-21
DE602004031959D1 (en) 2011-05-05
WO2005029169A1 (en) 2005-03-31
EP1668406B1 (en) 2011-03-23

Similar Documents

Publication Publication Date Title
USRE41632E1 (en) Liquid crystal display device and method of manufacturing the same
US7615336B2 (en) Method of fabricating a display device by using a stepped halftone mask to form a three-step photoresist pattern on a material layer for etching and ashing
US6344884B1 (en) Liquid crystal display device substrate and method for manufacturing thereof
US8053295B2 (en) Liquid crystal display device and method of fabricating the same
JP2003248232A (en) Liquid crystal display device and manufacturing method therefor
JP3964324B2 (en) Method for manufacturing transflective display device and transflective display device
US7518675B2 (en) Method of manufacturing liquid crystal display device
GB2314209A (en) Method of forming a thin film transistor electrode with a tapered edge
US6391499B1 (en) Light exposure mask and method of manufacturing the same
US20020191122A1 (en) Method of forming electrodes or pixel electrodes and a liquid crystal display device
US6746887B1 (en) Method of preventing a data pad of an array substrate from overetching
US20070264597A1 (en) Method for manufacturing transflective liquid crystal display
KR100542307B1 (en) TFT-LCD Manufacturing Method
JP4610552B2 (en) Manufacturing method of liquid crystal display device
US6204082B1 (en) Method of manufacturing liquid crystal display device
KR20080004898A (en) Array substrate of transflective type fringe field switching mode liquid crystal display and the method thereof
JP2007114811A (en) Method of manufacturing liquid crystal display device
JP2001305515A (en) Method and device for manufacturing reflection type liquid crystal display device
KR100701667B1 (en) Transflective type liquid crystal display and method for manufacturing the same
JP2007193371A (en) Liquid crystal display device
KR19980060019A (en) Method of manufacturing thin film transistor substrate
KR20030058514A (en) Method for fabricating reflective lcd
KR20040033416A (en) Method of manufacturing semitransmission type liquid crystal display

Legal Events

Date Code Title Description
AS Assignment

Owner name: KONINKLIJKE PHILIPS ELECTRONICS, N.V., NETHERLANDS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TANAKA, HIDEO;REEL/FRAME:017715/0459

Effective date: 20060126

AS Assignment

Owner name: TPO HONG KONG HOLDING LIMITED, CHINA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KONINKLIJKE PHILIPS ELECTRONICS N.V.;REEL/FRAME:019193/0404

Effective date: 20070411

AS Assignment

Owner name: TPO HONG KONG HOLDING LIMITED, CHINA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KONINKLIJKE PHILIPS ELECTRONICS N.V.;REEL/FRAME:019265/0363

Effective date: 20070411

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

AS Assignment

Owner name: INNOLUX HONG KONG HOLDING LIMITED, HONG KONG

Free format text: CHANGE OF NAME;ASSIGNOR:TPO HONG KONG HOLDING LIMITED;REEL/FRAME:050662/0619

Effective date: 20141212

AS Assignment

Owner name: INNOLUX HONG KONG HOLDING LIMITED, HONG KONG

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INNOLUX CORPORATION;REEL/FRAME:050704/0082

Effective date: 20190714

AS Assignment

Owner name: INNOLUX CORPORATION, TAIWAN

Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNOR/ASSIGNEE PREVIOUSLY RECORDED AT REEL: 050704 FRAME: 0082. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNOR:INNOLUX HONG KONG HOLDING LIMITED;REEL/FRAME:050991/0313

Effective date: 20190714

Owner name: INNOLUX CORPORATION, TAIWAN

Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE/ASSIGNOR PREVIOUSLY RECORDED AT REEL: 050704 FRAME: 0082. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNOR:INNOLUX HONG KONG HOLDING LIMITED;REEL/FRAME:050991/0872

Effective date: 20190714

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20210414